Topic: US Coast Guard 45 RBm (Graupner Pilot Boat) (Read 28687 times)

tonyH · « **Reply #75 on:** June 02, 2018, 01:09:14 pm »

I'm glad you said "almost easy" Umi. Not easy to get it looking as 'right' as you have

The FRB motors were only standard 540 outboards from, I think, Kyosho so the Graupner ones would fit the bill easily now. The guy who bought it decided to upgrade it and so it was last seen in flames in he middle of the lake - Happy days

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Umi_Ryuzuki · « **Reply #76 on:** June 02, 2018, 10:24:26 pm »

Quote

and so it was last seen in flames in he middle of the lake

So there are still a few things to work on... Today, Boat hooks.

hama · « **Reply #77 on:** June 02, 2018, 10:49:53 pm »

But seriously, is this the model or the real thing!!

Hama

Umi_Ryuzuki · « **Reply #78 on:** June 02, 2018, 11:04:44 pm »

Quote from: hama on June 02, 2018, 10:49:53 pm

But seriously, is this the model or the real thing!!
Hama

It's the model....

tonyH · « **Reply #79 on:** June 03, 2018, 04:56:49 pm »

Hi Umi,
Have a look at RCGroups forum. Hansen Dam Lake "Irregulars" Page 128 for the FRB. I almost feel like building another

Xtian29 · « **Reply #80 on:** June 03, 2018, 06:26:04 pm »

The direct link

https://www.rcgroups.com/forums/showthread.php?501819-Hansen-Dam-Lake-Irregulars-Report/page128

Umi I'm surprised with your need of more grip and adding skegs - from my side after last summer trial with the one of a friend and looking to your pictures when sailing I'm thinking about small flaps to help the boat to stay horizontal instead of nose-up

tonyH · « **Reply #81 on:** June 03, 2018, 06:56:35 pm »

Hi Xtian,
How is Phil?I presume his RB-M was a bit more successful than mine?
The real RB-M had the anti-skid fins.
Kind Regards
Tony
PS The Hansen Dam Lake boat is the FRB I built and not the RB-M that Phil built and I scrapped!

Xtian29 · « **Reply #82 on:** June 03, 2018, 07:48:43 pm »

Yes there is small skegs but also the flaps -

Then when I made "sea-trial" (without skegs and flaps) I experienced no problem with stern drift - on the other hand, the boat was a little bit "nose up" instead of horizontal like this one (very nice canadian livery)

Umi_Ryuzuki · « **Reply #83 on:** June 03, 2018, 10:28:20 pm »

Very nice Tony

https://www.rcgroups.com/forums/showpost.php?p=10033995&postcount=1927
https://www.rcgroups.com/forums/showpost.php?p=10035010&postcount=1936
Oh no...

.

I don't think I want to add trim plates.I'll stick to moving the battery around.

The nice thing about building the Canadian version, is the deck is grey, no anti skid.

Umi_Ryuzuki · « **Reply #84 on:** June 04, 2018, 08:15:56 am »

Pushing the punch list of things to do, Got the anchor set into place, and
soldered up the gun mount for the bow. Still have a top plate to create and place on the mount.

I wanted to silver solder the base washers, but I knew the wood might give me an issue.
Of course it flamed up, and off gassed and didn't solder a thing, so I cleaned it up, and just
used electrical solder down there.

.

Umi_Ryuzuki · « **Reply #85 on:** June 05, 2018, 07:07:02 pm »

Finished up the gun mount with a styrene top plate.
It was just easier to mill the slots than a brass washer.

Added a convertible bow fairlead also. I was working toward putting a nut into
one side of the fairfairlead, then thought, "How often am I going to open this up, and actually use it?"

Derp... so I just soldered a T-handle to the screw, and threaded it into the material(renshape).
.

Umi_Ryuzuki · « **Reply #86 on:** June 11, 2018, 12:13:37 am »

Keith Schermerhorn caught a photo of my CG45 cruising through the maneuvering course up North in Seattle.

I had to run the course with the buckets about 40 percent down, to keep the
speed slow enough to make it through the obstacles and gates.

hama · « **Reply #87 on:** June 11, 2018, 03:09:05 pm »

Well done! She looks fantastic

Hama

TugCowboy · « **Reply #88 on:** June 11, 2018, 04:08:19 pm »

Looks absolutely real. Brilliant modelling Skills Umi

tonyH · « **Reply #89 on:** June 11, 2018, 06:42:41 pm »

It's a really superb build-up Umi.
I was wondering whether the Tamiya Rally Crew at 1:24...........

Umi_Ryuzuki · « **Reply #90 on:** July 22, 2018, 04:19:02 am »

Here's a befuddlment, Crabbing, or side stepping the model is proving to be difficult.

I am set up with single, or ganged steering, single throttle, and separate reverse bucket control.But thrust from the reverse buckets is sort of backwards compared to rudder and propeller.

tonyH · « **Reply #91 on:** July 22, 2018, 12:47:27 pm »

I'd have thought with the type of reversing buckets on the RBM that the thrust is split to both sides and not just as shown on the right hand sketch? You'd have to reduce the power to the port drive. since only a proportion of the thrust from the starboard drive would be backwards.
Just an idea

Xtian29 · « **Reply #92 on:** July 22, 2018, 04:04:22 pm »

Hello

Side stepping is quite easy with the Graupner Multijet but it need 4 channels - 2 per waterjet : direction + bucket

It's the option on my pilotboat - I built a 3D support for the 4 servos and above it's like a shelf for the 2 esc + reception

and side-stepping in the pond

https://www.youtube.com/watch?v=MOuJwzDZCGA&feature=youtu.be

Xtian

Perkasaman2 · « **Reply #93 on:** July 22, 2018, 04:53:17 pm »

Excellent crabbing in the video.

Umi_Ryuzuki · « **Reply #94 on:** July 22, 2018, 06:18:57 pm »

Nicely built Xtian, and the video makes it look too easy.
I am having a hard time with the single rudder control, so I also posted on RCgroups.
Capt. Troy came back with some instructions...

Quote

The simplest way to crab these jet boats is:

1) Set your throttle to the minimum you need to move the boat and don't touch it again.

2) Dump the bucket (full astern) on the side you want to crab towards, and don't touch it again.

3) Set the bucket on the opposite side of your crab direction to half ahead and use this bucket to control your fore and aft
motion relative towards whatever you're walking towards, i.e., if you want to crab towards a ship's gangway and you see that
the boat is creeping ahead, then pull the bucket back a touch until the headway stops and vice versa.

4) Keep your other free hand on the helm and use this to control the angle of your walk, so if you're crabbing towards a dock
and you want to land flat, but the bow is going to touch down first, use the helm to steer the bow out just as if were driving
with headway.

I just had my buddy bring our new boat under the office window and I took this quick video for you;

And posted a video...

https://www.youtube.com/watch?v=XyvuDbu3kJ8&feature=youtu.be

...
..
.

So I'll have to have another go at this as built.

Xtian29 · « **Reply #95 on:** July 22, 2018, 06:32:44 pm »

Thanks Aimée for the video "scale 1"

In fact it's not complicated and quite the same as aboard an ASD tug

tonyH · « **Reply #96 on:** July 23, 2018, 12:44:18 pm »

The Kamewa buckets on the real boats have an advantage because they are closed on the lower side so act rather like two tubes rather than open buckets. Better control because less wasted downwards.
Tony

Umi_Ryuzuki · « **Reply #97 on:** July 23, 2018, 05:21:41 pm »

I don't think the downward thust is an issue with the open bucket on the graupner, but
when the buckets are down, they do tend to aerate the drive intake when in reverse.
I have wondered if closing them up across the ends or designing new buckets would reduce the aeration.

tonyH · « **Reply #98 on:** July 23, 2018, 08:10:07 pm »

If you go back to post 74, there's a pic of the buckets I made which are based on the prototype ones from USCG. You'll see that they had an internal duct which was correct at the time. I know they've been modified by KaMeWa since so they look/perform even more like pipes so if you google KaMeWa 375S which is the standard spec, you should have a better idea.
It's one of those things that could be worth an experiment

Umi_Ryuzuki · « **Reply #99 on:** August 12, 2018, 09:51:43 pm »

Yea!! I had the boat crabbing last night.

It was done as suggested above, but being that it was dark, I don't have any video.

News:

Author Topic: US Coast Guard 45 RBm (Graupner Pilot Boat) (Read 28687 times)